Development of a validation technique for road surface profile applicable to point cloud data

In recent years, various information and communication technology (ICT) devices measuring three-dimensional (3D) point cloud data have been developed and widely used for the application of pavement surface investigation. However, ICT devices have generally been developed not only for measuring road surface profiles but for various geo-reference point clouds. In this background, the validation of surface profiles acquired with ICT devices fulfils an important role in proving the reliability of measurement result composed by point clouds. This study proposes a wavelet transform agreement (WTA) which involves a normalization factor of profile amplitude for further improvement in the wavelet-based coherence technique. The WTA analysis allows evaluating similarity/dissimilarity of two profiles considering both the location and wavelength simultaneously. For this purpose, a terrestrial laser scanner (TLS), a mobile mapping system (MMS), and an unmanned aerial vehicle (UAV) are employed to prove the advantage of WTA in practical applications. As a result, the advantages of WTA analysis are clearly recognized in the optimization for the measurement interval of TLS, the multi-line measurement of MMS for ride quality improvement of a pavement, and the efficient operation of UAV in terms of the flight altitude. This paper also shows the identification of aging development for surface roughness over time in terms of locations and wavelengths. These findings help not only to guarantee the accuracy of profile measurements but to realize the sophisticated way of using 3D point clouds acquired with ICT devices. The outcomes of this study contribute to the increase of productivity for pavement works with improving the quality of surface profile measurement.